Mashing
In a 10-galloln insulated cooler, combine the crushed malts with 3 gallons plus 12 cups of 172°F water. The water should cool slightly when mixed with the grain. Hold the mash at 156°F for 20 minutes.
Add 2 gallons plus 2 cups of 184°F water. The mixture should come up to 165°F.
Lautering & Sparging
Lauter the mash. Once the liquid is lower than the level of the grain, begin to slowly sprinkle 3 gallons plus 1 cup of 168°F water over the grains to start the sparge. Continue sparging.
The Boil
Set the brew kettle of wort on top of a propane burner and add water to bring the wort level up to about 6 gallons plus 12 cups, if needed. Bring the wort to a rapid, rolling boil. As it begins to come to a boil, a layer of foam and scum may develop at the surface. Skim it off and discard. Once the wort is at a full boil, put a hops bag containing the Columbus hops in the kettle and set a timer for 90 minutes. Stir the wort frequently during the boil and be watchful to avoid boil-overs.
At 15 minutes before the end of the boil, stir in the Irish moss. At 10 minutes before the end of the boil, put a hops bag containing the 0.77 ounce of Ahtanum hops in the kettle. When the boiling time is over, turn off the heat and put a hops bag containing the remaining Ahtanum hops in the kettle. Cover the kettle and immediately begin cooling the wort as quickly as possible.
Pitching Yeast & Fermentation
Once the wort has cooled to 72°F, discard the spent hops and check the specific gravity of the wort with a hydrometer. The target starting gravity is 1.057 (14 Plato).
Transfer the wort to the primary fermentation bucket. Pitch the yeast (or prepare a yeast starter).
Allow the wort to ferment through primary and secondary fermentation at 72°F until it reaches a specific gravity of 1.014 (3.5 Plato).